Climate experts expect unpredictable El Niño to weaken this spring

By on January 15, 2016
The Western U.S. December 2015 percent of normal precipitation. (Images from WestWide Drought Tracker, Western Region Climate Center; University of Idaho/courtesy of Greg Jones).

The Western U.S. December 2015 percent of normal precipitation. (Images from WestWide Drought Tracker, Western Region Climate Center; University of Idaho/courtesy of Greg Jones).

ASHLAND, Ore. — El Niño didn’t perform as predicted this winter, but skiers, irrigators and farmers in the Pacific Northwest don’t mind.

Greg Jones, a Southern Oregon University professor and one of the wine world’s leading figures on climate change, issued on Thursday the first in his year-long series of reports for the Pacific Northwest wine industry.

“Finally a winter,” Jones wrote. “(There’s) relief from the drought, but too much, too quickly for some.”

Next month, Jones will make presentations at both the Oregon Wine Symposium and the Idaho Wine Commission’s annual meeting. This week’s news release provided a preview of those talks.

“The December precipitation pattern over the West was nearly opposite of what would be expected in a normal El Niño year,” Jones wrote. “From Northern California into the PNW and Canada, the region saw 200 percent or more above normal precipitation, while much of Southern California and into the Southwest saw much below normal precipitation.

“The rest of the U.S. was mixed with a dry December into much of the Great Basin and scattered across the Rockies, while much of the Midwest and Southeast were substantially wetter than normal,” he continued. “Again, so far this El Niño is not behaving like other recent large events.”

Snowpack in some regions unlikely to fully recharge

Western U.S. percent of normal precipitation from January through December 2015 from normal (Images from WestWide Drought Tracker, Western Region Climate Center; University of Idaho).

Western U.S. percent of normal precipitation from January through December 2015 from normal. (Image from WestWide Drought Tracker, Western Region Climate Center; University of Idaho).

And while California irrigators appreciate the snowfall, Jones points out it will take more than a month or two of precipitation for those reservoirs to fully recharge.

“Also, snowpacks over the western U.S. are in much better shape than they were at this time last year. But we still have a long way to go to get to the average for the water year,” Jones wrote.

Jones said this atypical El Niño pattern in the Pacific Northwest has resulted in “much greater precipitation than would be expected, while it has been colder than normal. While in Northern California, precipitation in the winter is trailing the amounts during the start of the previous largest appearances of El Niños (1997 and 1982).”

The University of Virginia grad pointed out many portions of the East Coast were warmer than normal on Christmas Day, noting “the eastern U.S. experienced one of its warmest Decembers on record … quite a difference from the previous December with feet of snow on the ground.”

2015 on track as planet’s warmest in modern times

Global sea surface temperatures (°C) for the period ending Jan. 14, 2016 (Image from National Oceanic and Atmospheric Administration (NOAA) and National Environmental Satellite, Data, and Information Service (NESDIS).

Global sea surface temperatures (°C) for the period on Jan. 14, 2016. (Image from National Oceanic and Atmospheric Administration (NOAA) and National Environmental Satellite, Data, and Information Service (NESDIS).

On the other hand, December capped a year that was warmer than normal throughout the West Coast.

“Average temperatures ended up 1.0-4.0°F or more above the 1981-2010 climate normal, especially in the PNW where up to 6°F above normal was seen in some areas,” Jones wrote. “This pattern continues across the entire U.S., but with temperature differences from the Plains to the Midwest, Southeast and Eastern U.S. not as much as we saw in the West, running 1.0-2.0°F.

“Again, globally 2015 is on track to be the warmest year since good records have been keep (beating the record set last year),” Jones added.

That also influences the precipitation amounts.

“The U.S. Drought Monitor in early January reflects the 2015 rainfall pattern with continued dry conditions in much of the West, and a return to normal conditions in the PNW and much of the rest of the U.S.” Jones wrote.

And while the El Niño advisory continues, the Climate Prediction Center reports this strong El Niño will weaken and become El Niño Southern Oscillation-neutral during the late spring or early summer.

“The forecasters from many governments in the Pacific are in agreement with the general model consensus, though the exact timing of the transition is difficult to predict,” Jones wrote. “However, El Niño effects throughout the region are expected to continue as there is a lag time from when the ocean temperatures shift to when the atmosphere responds.”

Forecast periods

Current U.S. Drought Monitor

Current U.S. Drought Monitor

6-10 day: Forecast is tending warm and wet over most of the western U.S. while the eastern half of the country will likely see cooler and drier conditions. This is due to slight shift to a trough over the North Pacific, ridge over the western U.S., and a trough into the Midwest and eastern U.S. The trough in the North Pacific will spin off a series of storms into the western U.S. keeping the precipitation levels near normal to greater than normal for the west coast for this time of year.

8-14 days: Does not deviate much from the 6-10 day forecast with the overall pattern dominated by a greater chance of warm/wet in the west and cool/dry in the east. Circulation over the North Pacific is likely to continue favoring frequent storms tracking into the western U.S.

30 days: Forecast through the rest of January is holding to a more classic El Niño pattern with a likelihood of warm and relatively dry conditions from the PNW east across the northern tier of states and wet/warm in Southern California then wet/cold across the southern states.

90 days: Even with some slight departures over the first half of the winter from the expected El Niño patterns, the January-February-March (JFM) forecast continues to be dominated by more classic El Niño patterns in expected temperatures and precipitation. The JFM forecast exhibits a greater chance of broader warmer-than-average conditions in the western U.S. and across the northern states. For precipitation, the JFM outlook tilts the odds to near normal to below median precipitation in the PNW and across the northern Rockies and into the Great Lakes.

About Eric Degerman

Eric Degerman is the president and CEO of Great Northwest Wine. He is a journalist with more than 30 years of daily newspaper experience and has been writing about wine since 1998. He co-founded Wine Press Northwest with Andy Perdue and served as its managing editor for 15 years. He is a frequent wine judge along the West Coast and contributor to Pacific Northwest Golfer magazine, the region's longest-running golf publication.

One Comment

  1. Dan

    January 15, 2016 at 9:05 am

    When did El Nino’s and/or weather become “predictable”?

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